In addition, a large number of hydrogen bonds are formed between the hydroxyl groups in the PEGO segment and PVDF, which induces the formation of 98 % ultrahigh content polar phase. Consequently, when the electric field strength is 528 MV/m, the composite film obtains a high energy-storage ...
Key words:polar phase; PVDF; films; crystallization conditions; solution-cast 引言 聚偏氟乙烯(poly(vinylidene fluoride,简称PVDF))作为目前压电性能最为优良的一类高分子材料,已广泛应用于传感器,致动器,发电机等各个领域[1]。PVDF是一类半结晶聚合物,具有五种不同的晶型,分别为α、β、γ、δ、ε相,其中...
The C–F bonds are polar. The highest dipole moment is obtained with the alignment of all dipoles of the polymer in the same direction. This corresponds to the β-phase of the PVDF. β-phase is the desired phase for the piezoelectric characteristics of the polymer. ...
polar crystalline transited from non polar crystalline So it was found that the crystalline degree crystalline content and remanent polarization of thermally poled PVDF films were higher than those of corona charged PVDF films The reason that caused leakage current was also analyzed The space charges...
completely,whichcausedmorepolar crystallinetransitedfromnon-polarαcrystalline.Soitwasfoundthatthe crystallinedegree, crystallinecontentandremanentpolarizationofthermallypoledPVDFfilmswerehigherthan thoseofcoronachargedPVDFfilms.Thereasonthatcausedleakagecurrentwasalsoanalyzed.Thespacecharges injectedduringthepolingprocesswer...
This enhances the nanoparticles nucleation and the piezo electric polar β-phase can be stabilized by surface charge induced polarization46. In addition, by an application of mechanical force, the crystal structure of the PVDF-HFP/Co-ZnO fibers were deformed and the external pressure creates a ...
Bacterial CellulosePVDF-bacterialAcetobacter xylinumPolyvinylidene fluoride (PVDF) is a smart material owing to its pyro-, piezo- and ferroelectric properties. For practical application, e.g., as a sensor material however; the non-polar, low-energy, α-phase of PVDF must be transformed into ...
indicating that γ-phase was formed in the samples. The peak at 765 cm−1is ascribed to α-phase and remains unchanged after introduction of TiO2@SrTiO3@PDA NWs, indicating negligible phase transition from α-phase to γ-phase37. The polar γ-phase usually presents high breakdown strength,...
It was found that the polar phase fraction of the films was significantly enhanced by increasing the nanofiller concentration and the stretch ratio. Moreover, a finite element model was constructed to determine the true value of the strain during the tensile process and to calibrate the stretch ...
The peak at 765 cm−1 is ascribed to α-phase and remains unchanged after introduction of uTsiOua2l@lySprTreisOe3n@tsPhDigAhNbrWeask, dinodwincasttirnegnngtehg,liwgihbilcehpihsafsaevotrraanbsleitfioorn from α-phase enhancing the to γ-phase37. The energy density of polar γ-...